Not with a .300 RUM, but most of the elk that I have killed were with .30 caliber 180 grain bullets. I shot 7 elk with 180 grain Sierra GameKing bullets from my .30-06 and 21 elk and 2 bull moose with 180 grain Partitions from my .30 Gibbs. My last 2 bull elk were shot with a 168 grain TSX and a 168 grain TTSX bullet from my .300 Weatherby. The other elk that I've killed were with a .30-40 Krag (the only elk that I've shot with a factory cartridge), a .30-06 150 grain Hornady Spire Point bullet, an arrow, a 117 grain Sierra GameKing bullet from my .257 Ackley, and a 160 grain Accubond from my 7 mm RM. I shot all of those animals on DIY hunts, and most were on DIY solo hunts, and all were shot at less than 300 yards.
My current elk load is 180 grain TTSX bullets from my .300 Weatherby. I've never seen the need for any .30 caliber bullets heavier than 180 grains.
